package com.lll.library.view;

/*
 * Copyright (C) 2012 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import android.app.Activity;
import android.app.LocalActivityManager;
import android.content.Context;
import android.content.res.TypedArray;
import android.os.Bundle;
import android.os.Parcel;
import android.os.Parcelable;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.widget.FrameLayout;
import android.widget.LinearLayout;
import android.widget.TabHost;
import android.widget.TabWidget;

import java.util.ArrayList;

public class MainFragmentTabHost extends TabHost implements TabHost.OnTabChangeListener
{

    private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>();

    private FrameLayout mRealTabContent;

    private Context mContext;

    private FragmentManager mFragmentManager;

    private int mContainerId;

    private OnTabChangeListener mOnTabChangeListener;

    private TabInfo mLastTab;

    private boolean mAttached;

    static final class TabInfo
    {
        private final String tag;

        private final Class<?> clss;

        private final Bundle args;

        private Fragment fragment;

        TabInfo(String _tag, Class<?> _class, Bundle _args)
        {
            tag = _tag;
            clss = _class;
            args = _args;
        }
    }

    static class DummyTabFactory implements TabContentFactory
    {
        private final Context mContext;

        public DummyTabFactory(Context context)
        {
            mContext = context;
        }

        @Override
        public View createTabContent(String tag)
        {
            View v = new View(mContext);
            v.setMinimumWidth(0);
            v.setMinimumHeight(0);
            return v;
        }
    }

    static class SavedState extends BaseSavedState
    {
        String curTab;

        SavedState(Parcelable superState)
        {
            super(superState);
        }

        private SavedState(Parcel in)
        {
            super(in);
            curTab = in.readString();
        }

        @Override
        public void writeToParcel(Parcel out, int flags)
        {
            super.writeToParcel(out, flags);
            out.writeString(curTab);
        }

        @Override
        public String toString()
        {
            return "FragmentTabHost.SavedState{" + Integer.toHexString(System.identityHashCode(this)) + " curTab="
                    + curTab + "}";
        }

        public static final Creator<SavedState> CREATOR = new Creator<SavedState>()
        {
            public SavedState createFromParcel(Parcel in)
            {
                return new SavedState(in);
            }

            public SavedState[] newArray(int size)
            {
                return new SavedState[size];
            }
        };
    }

    public MainFragmentTabHost(Context context)
    {
        // Note that we call through to the version that takes an
        // AttributeSet,
        // because the simple Context construct can result in a broken object!
        super(context, null);
        initFragmentTabHost(context, null);
    }

    public MainFragmentTabHost(Context context, AttributeSet attrs)
    {
        super(context, attrs);
        initFragmentTabHost(context, attrs);
    }

    private void initFragmentTabHost(Context context, AttributeSet attrs)
    {
        TypedArray a = context.obtainStyledAttributes(attrs, new int[] {android.R.attr.inflatedId}, 0, 0);
        mContainerId = a.getResourceId(0, 0);
        a.recycle();

        super.setOnTabChangedListener(this);
    }

    private void ensureHierarchy(Context context)
    {
        // If owner hasn't made its own view hierarchy, then as a convenience
        // we will construct a standard one here.
        if (findViewById(android.R.id.tabs) == null)
        {
            LinearLayout ll = new LinearLayout(context);
            ll.setOrientation(LinearLayout.VERTICAL);
            addView(ll, new LayoutParams(ViewGroup.LayoutParams.FILL_PARENT,
                    ViewGroup.LayoutParams.FILL_PARENT));

            TabWidget tw = new TabWidget(context);
            tw.setId(android.R.id.tabs);
            tw.setOrientation(TabWidget.HORIZONTAL);
            ll.addView(tw, new LinearLayout.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT,
                    ViewGroup.LayoutParams.WRAP_CONTENT, 0));

            FrameLayout fl = new FrameLayout(context);
            fl.setId(android.R.id.tabcontent);
            ll.addView(fl, new LinearLayout.LayoutParams(0, 0, 0));

            mRealTabContent = fl = new FrameLayout(context);
            mRealTabContent.setId(mContainerId);
            ll.addView(fl, new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT, 0, 1));
        }
    }



    public void setup(Context context, FragmentManager manager)
    {
        ensureHierarchy(context); // Ensure views required by super.setup()
        super.setup();
        mContext = context;
        mFragmentManager = manager;
        ensureContent();
    }

    public void setup(Context context, FragmentManager manager, int containerId)
    {
        ensureHierarchy(context); // Ensure views required by super.setup()
        super.setup();
        mContext = context;
        mFragmentManager = manager;
        mContainerId = containerId;
        ensureContent();
        mRealTabContent.setId(containerId);

        // We must have an ID to be able to save/restore our state. If
        // the owner hasn't set one at this point, we will set it ourself.
        if (getId() == View.NO_ID)
        {
            setId(android.R.id.tabhost);
        }
    }

    @Override
    public void setup(LocalActivityManager activityGroup) {
        super.setup(activityGroup);
    }


    private void ensureContent()
    {
        if (mRealTabContent == null)
        {
            mRealTabContent = (FrameLayout) ((Activity) getContext()).findViewById(mContainerId);
            if (mRealTabContent == null)
            {
                throw new IllegalStateException("No tab content FrameLayout found for id " + mContainerId);
            }
        }
    }

    @Override
    public void setOnTabChangedListener(OnTabChangeListener l)
    {
        mOnTabChangeListener = l;
    }

    public void addTab(TabSpec tabSpec, Class<?> clss, Bundle args)
    {
        tabSpec.setContent(new DummyTabFactory(mContext));
        String tag = tabSpec.getTag();

        TabInfo info = new TabInfo(tag, clss, args);

        if (mAttached)
        {
            // If we are already attached to the window, then check to make
            // sure this tab's fragment is inactive if it exists. This
            // shouldn't
            // normally happen.
            info.fragment = mFragmentManager.findFragmentByTag(tag);
            if (info.fragment != null && !info.fragment.isDetached())
            {
                FragmentTransaction ft = mFragmentManager.beginTransaction();
                ft.detach(info.fragment);
                ft.commit();
            }
        }

        mTabs.add(info);
        addTab(tabSpec);
    }

    @Override
    protected void onAttachedToWindow()
    {
        super.onAttachedToWindow();
        if (!commitEnabled)
        {
            return;
        }
    }

    public void initFragments()
    {

        String currentTab = getCurrentTabTag();

        // Go through all tabs and make sure their fragments match
        // the correct state.
        FragmentTransaction ft = null;
        for (int i = 0; i < mTabs.size(); i++)
        {
            TabInfo tab = mTabs.get(i);
            tab.fragment = mFragmentManager.findFragmentByTag(tab.tag);
            if (tab.fragment != null && !tab.fragment.isDetached())
            {
                if (tab.tag.equals(currentTab))
                {
                    // The fragment for this tab is already there and
                    // active, and it is what we really want to have
                    // as the current tab. Nothing to do.
                    mLastTab = tab;
                }
                else
                {
                    // This fragment was restored in the active state,
                    // but is not the current tab. Deactivate it.
                    if (ft == null)
                    {
                        ft = mFragmentManager.beginTransaction();
                    }
                    ft.detach(tab.fragment);
                }
            }
        }

        // We are now ready to go. Make sure we are switched to the
        // correct tab.
        mAttached = true;
        ft = doTabChanged(currentTab, ft);
        if (ft != null)
        {
            ft.commit();
            mFragmentManager.executePendingTransactions();
        }
    }

    @Override
    protected void onDetachedFromWindow()
    {
        super.onDetachedFromWindow();
        mAttached = false;
    }

    @Override
    protected Parcelable onSaveInstanceState()
    {
        Parcelable superState = super.onSaveInstanceState();
        SavedState ss = new SavedState(superState);
        ss.curTab = getCurrentTabTag();
        return ss;
    }

    @Override
    protected void onRestoreInstanceState(Parcelable state)
    {
        SavedState ss = (SavedState) state;
        super.onRestoreInstanceState(ss.getSuperState());
        setCurrentTabByTag(ss.curTab);
    }

    @Override
    public void onTabChanged(String tabId)
    {
        if (mAttached && commitEnabled)
        {
            FragmentTransaction ft = doTabChanged(tabId, null);
            if (ft != null)
            {
                ft.commit();
            }
        }

        if (mOnTabChangeListener != null)
        {
            mOnTabChangeListener.onTabChanged(tabId);
        }
    }

    private FragmentTransaction doTabChanged(String tabId, FragmentTransaction ft)
    {
        TabInfo newTab = null;
        for (int i = 0; i < mTabs.size(); i++)
        {
            TabInfo tab = mTabs.get(i);
            if (tab.tag.equals(tabId))
            {
                newTab = tab;
            }
        }
        if (newTab == null)
        {
            throw new IllegalStateException("No tab known for tag " + tabId);
        }
        if (mLastTab != newTab)
        {
            if (ft == null)
            {
                ft = mFragmentManager.beginTransaction();
            }
            if (mLastTab != null)
            {
                if (mLastTab.fragment != null)
                {
                    ft.detach(mLastTab.fragment);
                }
            }
            if (newTab != null)
            {
                if (newTab.fragment == null)
                {
                    newTab.fragment = Fragment.instantiate(mContext, newTab.clss.getName(), newTab.args);
                    ft.add(mContainerId, newTab.fragment, newTab.tag);
                }
                else
                {
                    ft.attach(newTab.fragment);
                }
            }

            mLastTab = newTab;
        }
        return ft;
    }

    private boolean commitEnabled;

    public void setCommitEnabled(boolean enable)
    {
        commitEnabled = enable;
    }
}
